Steering a snowmobile is typically accomplished by a pair of steering skis pivotally attached to the front of the snowmobile. The steering skis glide over the surface of the snow and may be angularly turned from side-to-side in response to movement of a handlebar grasped by a user. The snowmobile generally follows in the direction the steering skis are pointed.
Under most snow conditions steering skis, when turned, have a tendency to slide sideways, i.e. “plow” forward over the surface of the snow rather than tracking as intended. The turning radius of the snowmobile thus becomes larger than anticipated, and may result in “understeering”. This phenomenon generally increases as the speed of the snowmobile increases.
Various methods have been employed to lend increased predictability and control to snowmobile steering skis. One of the most common methods is the inclusion of one or more longitudinal keels along the underside or running surface of the steering ski. The keel generally cuts or bites into the surface of the snow and enhances steering characteristics of the skis. Some keels can also be further provided with a metallic wear bar to reduce the wear on the keel and to extend its life.
However, steering skis equipped with keel(s) leave a more or less deep impression, or trace, in the snow corresponding to the profile of the ski, keel(s), and metallic wear bar(s). Particularly in wet and/or compacted snow, a steering ski coming upon the impression left by a previous steering ski will tend to follow the same track, especially if the temperature has dropped, causing the wet snow to freeze. This effect is generally known as “darting”. Darting forces the snowmobile user to compensate or correct for the darting by counter-steering the snowmobile to maintain directional stability. Darting can sometimes be quite severe, particularly if the snow containing the initial track was wet and has refrozen (such as on a sunny winter day followed by a cold night, which is typical snowmobiling weather).
Yet, despite considerable developments in the field of snowmobile steering skis, the problem of darting has still not been properly addressed. There is thus a need for a snowmobile steering ski which at least mitigates the problem of darting.